Proof Research Barrel Features Proof s Caliber Matched Gas System or CAMGAS tunes the gas port location specifically to the .223 Wylde chambering and 18 inch barrel length rather than relying on a generic AR-15 gas system layout. The AR-15 platform was originally designed around the .223 Remington and 5.56 NATO cartridges and higher performance loads can leave bore pressure elevated further down the barrel than the platform was built around. By matching the gas system to this specific cartridge and length Proof s engineering reduces felt recoil and results in less fouling making its way back into the receiver. That translates directly into increased reliability of extraction and reduced wear and tear on brass over time. Machined from stainless steel with a 1 in 7 twist rate this barrel is built to stabilize a wide range of .223 Wylde bullet weights giving shooters flexibility in load selection. The 18 inch length balances velocity gains with a barrel profile still practical for a general purpose AR-15 build. A threaded muzzle in the common 1/2x28 pattern lets shooters add a compensator or suppressor without additional gunsmithing. For AR-15 builders chasing both accuracy and dependable functioning from their rifle this Proof Research drop in barrel delivers a tuned high performance upgrade over a stock factory barrel. Proof Research Barrel Specifications Manufacturer: Proof Research Model: Barrel Caliber: .223 Wylde Barrel Length: 18 Barrel Material: Stainless Steel Twist Rate: 1:7 Muzzle Thread: 1/2x28 Color: Silver Compatible Hosts: AR-15 Available At: GrabAGun